Extracted stay points:
laltitude	longitude	arriving time	leaving time
39.95801199473682 116.35734513508778 2009-07-02,03:23:18 2009-07-02,04:27:08
39.960392627450986 116.36310567647061 2009-07-02,04:34:23 2009-07-02,05:30:58
39.99560809738717 116.31017742042748 2009-07-02,07:29:12 2009-07-02,08:28:22
